Vietnam's performance has been abysmal in cracking down against the illegal trade of animal parts that is threatening the survival of elephants, rhinos and tigers, according to a new report by the WWF.

The "Wildlife Crime Scorecard" report compiled the international conservation group rated 23 African and Asian nations known for high levels of poaching and trafficking in ivory, rhino horn and tiger parts.

It issued countries scores of red, yellow or green to signal failure, partial failure or progress.

The three countries that scored the lowest on the environmental report card were Vietnam, Laos and Mozambique, all of which received two red scores.

Vietnam received its two red scores for its failure to stop the trade of rhino and tiger parts. Vietnam was identified in the report as the top destination worldwide for rhino horn, which has fueled a poaching crisis in South Africa.

According to the report, many Vietnamese, including some diplomats, have been arrested or implicated in South Africa for acquiring rhino horns illegally.

"It is time for Vietnam to face the fact that its illegal consumption of rhino horn is driving the widespread poaching of endangered rhinos in Africa, and that it must crack down on the illegal rhino horn trade," said Elisabeth McLellan, Global Species Program manager at the WWF.

"Vietnam should review its penalties and immediately curtail retail markets, including Internet advertising for horn."

A record 448 South African rhinos were killed for their horns in 2011 and the country, which itself received a yellow for rhinos, has lost an additional 262 already this year.

According to the report, Laos and Vietnam had failed to report how they would comply with a ban on the captive breeding of tigers for medicine, it added. Laos was also found to be failing to control the ivory trade.

Meanwhile, Mozambique had failed to halt the involvement of its citizens in rhino poaching in South Africa and had not controlled the ivory trade despite some improved checks at ports.

Inadequate enforcement of domestic ivory markets in China was also highlighted in the report. China received a yellow score for elephants, indicating its failure to effectively police its legal ivory markets.

Thailand received a red score for its failure to close a legal loophole that makes it easy for retailers to sell ivory from poached African elephants.

Bright spots from the report were green scores for India and Nepal for each of the three species groups. In 2011, Nepal celebrated a year without any rhino poaching incidents, which was largely attributed to improvements to its anti-poaching tactics and other law enforcement efforts.